when I open up TV Paint the pen tool power and size are set to P (pressure) which isn't what i want, I press reset and the size is set to P and the power is set to C (constant). So for some reason the tool isn't starting at its default setting.
Everytime i close and open the program the pen tool settings are back to the size and power set to P. How can I make it so that the size is P and the power is C as default?

most likely you have tvpaint set to reset to default after each new start.
you can change this in the preferences.

Edit> Preferences (CTRL-D)
under the tab: Start-up>
start-up configuration >
set it to : Remember last used configuration (or you can choose startup panel, thiswill offer you more configuration control each time you start up TVPaint

You can try resetting your configuration. But before doing so, export all your custom panels and shortcuts as they will be destroyed while resetting.
To reset, go to Preferences > Startup > Startup configuration > Open Startup Panel > OK.
Then restart the software and you will get this Statup Panel:

startup panel.png (32.71 KiB) Viewed 1716 times

Click on Delete to reset your default configuration and then on OK.

You will then get the software with its default configuration and will be able to load all your custom panels and shortcuts.